import { createReader, createWriter, Endian } from "bufferstuff";
import { WebSocketServer } from "ws";
import Fastify from "fastify";
import FastifyFormBody from "@fastify/formbody";
import FastifyCookie from "@fastify/cookie";
import FastifyView from "@fastify/view";
import EJS from "ejs";
import Config from "./objects/Config";
import FunkyArray from "./objects/FunkyArray";
import RemoteUser from "./objects/RemoteUser";
import { MessageType } from "./enums/MessageType";
import Database from "./objects/Database";
import { Console } from "hsconsole";
import UserService from "./services/UserService";
import UsernameData from "./interfaces/UsernameData";
import { randomBytes } from "crypto";
import SessionUser from "./objects/SessionUser";
import PasswordUtility from "./utilities/PasswordUtility";
import CreateEditPartyData from "./interfaces/CreateEditPartyData";
import JoinPartyData from "./interfaces/JoinPartyData";
import IdData from "./interfaces/IdData";
import Party from "./objects/Party";

Console.customHeader(`MultiProbe server started at ${new Date()}`);

const users = new FunkyArray<string, RemoteUser>();

new Database(Config.database.address, Config.database.port, Config.database.username, Config.database.password, Config.database.name);

// Web stuff

const sessions = new FunkyArray<string, SessionUser>();
const sessionExpiryInterval = setInterval(() => {
	const currentTime = Date.now();
	for (const key of sessions.keys) {
		const session = sessions.get(key);
		if (!session || (session && currentTime >= session.validityPeriod.getTime())) {
			sessions.remove(key);
		}
	}
}, 3600000);

const fastify = Fastify({
	logger: false
});

fastify.register(FastifyView, {
	engine: {
		ejs: EJS
	}
});

fastify.register(FastifyFormBody);

fastify.register(FastifyCookie, {
	secret: Config.session.secret,
	parseOptions: {
		path: "/",
		secure: true
	}
});

fastify.setNotFoundHandler(async (req, res) => {
	return res.status(404).view("templates/404.ejs", { });
});

function validateSession(cookies:{ [cookieName: string]: string | undefined }) {
	if ("MP_SESSION" in cookies && typeof(cookies["MP_SESSION"]) === "string") {
		const key = FastifyCookie.unsign(cookies["MP_SESSION"], Config.session.secret);
		if (key.valid && sessions.has(key.value ?? "badkey")) {
			return sessions.get(key.value ?? "badkey");
		}
	}

	return undefined;
}

// Get Methods

fastify.get("/", async (req, res) => {
	let session:SessionUser | undefined;
	if (session = validateSession(req.cookies)) {
		const user = await UserService.GetUser(session.userId);
		const parties = await UserService.GetUserParties(session.userId);
		const activeUserParty = await UserService.GetActiveParty(session.userId);
		if (user) {
			return res.view("templates/home.ejs", { user, parties, activeUserParty });
		}

		return res.view("templates/index.ejs", { });
	}

	return res.view("templates/index.ejs", { });
});

fastify.get("/account", async (req, res) => {
	return "TODO";
});

fastify.get("/account/login", async (req, res) => {
	return res.view("templates/account/login.ejs", { });
});

fastify.get("/account/register", async (req, res) => {
	return res.view("templates/account/register.ejs", { });
});

fastify.get("/account/logout", async (req, res) => {
	res.clearCookie("MP_SESSION");

	return res.redirect(302, "/");
});

fastify.get("/party/create", async (req, res) => {
	let session:SessionUser | undefined;
	if (!(session = validateSession(req.cookies))) {
		return res.redirect(302, "/");
	}

	return res.view("templates/party/createedit.ejs", { session });
});

fastify.get("/party/join", async (req, res) => {
	let session:SessionUser | undefined;
	if (!(session = validateSession(req.cookies))) {
		return res.redirect(302, "/");
	}

	return res.view("templates/party/join.ejs", { session });
});

fastify.get("/party/setactive", async (req, res) => {
	let session:SessionUser | undefined;
	if (!(session = validateSession(req.cookies))) {
		return res.redirect(302, "/");
	}

	const data = req.query as IdData;
	const numericId = parseInt(data.id ?? "-1");
	if (typeof(data.id) !== "string" || isNaN(numericId)) {
		return res.redirect(302, "/");
	}

	await UserService.SetActiveParty(session.userId, numericId);

	return res.redirect(302, "/");
});

fastify.get("/party/deactivate", async (req, res) => {
	let session:SessionUser | undefined;
	if (!(session = validateSession(req.cookies))) {
		return res.redirect(302, "/");
	}

	await UserService.DeactivateCurrentParty(session.userId);

	return res.redirect(302, "/");
});

// Post Methods

fastify.post("/account/register", async (req, res) => {
	const data = req.body as UsernameData;
	if (typeof(data.username) !== "string" || typeof(data.password) !== "string" || data.username.length > 32 || data.password.length < 8) {
		return res.view("templates/account/register.ejs", { });
	}

	const username = data.username.replaceAll("<", "&lt;").replaceAll(">", "&gt;");
	await UserService.CreateUser(0, username, data.password);

	const user = await UserService.GetUserByUsername(username);
	if (!user) {
		return res.view("templates/account/register.ejs", { });
	}

	const validPeriod = new Date();
	validPeriod.setTime(validPeriod.getTime() + Config.session.validity);
	const key = randomBytes(Config.session.length).toString("hex");

	sessions.set(key, new SessionUser(user.Id, validPeriod));

	res.setCookie("MP_SESSION", key, {
		path: "/",
		signed: true
	});

	return res.redirect(302, "/");
});

fastify.post("/account/login", async (req, res) => {
	const data = req.body as UsernameData;
	if (typeof(data.username) !== "string" || typeof(data.password) !== "string" || data.username.length > 32 || data.password.length < 8) {
		return res.view("templates/account/login.ejs", { });
	}

	const user = await UserService.GetUserByUsername(data.username);
	if (!user) {
		return res.view("templates/account/login.ejs", { });
	}

	if (await PasswordUtility.ValidatePassword(user.PasswordHash, user.PasswordSalt, data.password)) {
		const validPeriod = new Date();
		validPeriod.setTime(validPeriod.getTime() + Config.session.validity);
		const key = randomBytes(Config.session.length).toString("hex");

		sessions.set(key, new SessionUser(user.Id, validPeriod));

		res.setCookie("MP_SESSION", key, {
			path: "/",
			signed: true
		});

		return res.redirect(302, "/");
	}

	return res.view("templates/account/login.ejs", { });
});

fastify.post("/party/create", async (req, res) => {
	try {
		let session:SessionUser | undefined;
		if (!(session = validateSession(req.cookies))) {
			return res.redirect(302, "/");
		}

		const data = req.body as CreateEditPartyData;
		if (typeof(data.partyName) !== "string" || typeof(data.partyRef) !== "string" || data.partyName.length === 0 || data.partyRef.length === 0) {
			return res.view("templates/party/createedit.ejs", { session, partyName: data.partyName ?? "", partyRef: data.partyRef ?? "" });
		}

		const party = await UserService.GetPartyByPartyRef(data.partyRef)
		if (party != null) {
			return res.view("templates/party/createedit.ejs", { session, partyName: data.partyName ?? "", partyRef: data.partyRef ?? "", error: "A group with that Party ID already exists" });
		}

		await UserService.CreateParty(session.userId, data.partyName, data.partyRef);

		return res.redirect(302, "/");
	} catch (e) {
		console.error(e);
	}
});

fastify.post("/party/join", async (req, res) => {
	try {
		let session:SessionUser | undefined;
		if (!(session = validateSession(req.cookies))) {
			return res.redirect(302, "/");
		}

		const data = req.body as JoinPartyData;
		if (typeof(data.partyRef) !== "string" || data.partyRef.length === 0) {
			return res.view("templates/party/join.ejs", { partyRef: data.partyRef ?? "" });
		}

		const party = await UserService.GetPartyByPartyRef(data.partyRef);
		if (party == null) {
			return res.view("templates/party/join.ejs", { session, partyRef: data.partyRef ?? "", error: "That Join Code / Party ID is invalid." });
		}

		const userPartyExisting = await UserService.GetUserPartyForUser(session.userId, party.Id);
		if (userPartyExisting != null) {
			return res.view("templates/party/join.ejs", { session, partyRef: data.partyRef ?? "", error: "You are already in this group." });
		}

		await UserService.AddUserToParty(session.userId, party.Id);

		return res.redirect(302, "/");
	} catch (e) {
		console.error(e);
	}
});

// API

fastify.post("/api/login", async (req, res) => {
	res.header("access-control-allow-origin", "*");

	const data = req.body as UsernameData;
	if (typeof(data.username) !== "string" || typeof(data.password) !== "string" || data.username.length > 32 || data.password.length < 8) {
		return res.status(401).send("Username or Password incorrect");
	}

	const user = await UserService.GetUserByUsername(data.username);
	if (!user) {
		return res.status(401).send("Username or Password incorrect");
	}

	if (await PasswordUtility.ValidatePassword(user.PasswordHash, user.PasswordSalt, data.password)) {
		return res.status(200).send(user.APIKey);
	}

	return res.status(401).send("Username or Password incorrect");
});

let cachedVersion = "";
let cacheExpiry = 0;
fastify.post("/api/version", async (req, res) => {
	res.header("access-control-allow-origin", "*");

	if (Date.now() < cacheExpiry) {
		res.send(cachedVersion);
	} else {
		const response = await fetch(`http://${Config.githost}/tgpholly/t00-multiuser/raw/branch/master/client/Terminal-00-Multiuser.user.js?${Date.now()}`);
		if (response.status === 200) {
			const content = await response.text();
			if (content.includes("@version")) {
				cachedVersion = content.split("@version")[1].split("\n")[0].trim().split(".").join("");
				cacheExpiry = Date.now() + 30000;
				return res.send(cachedVersion);
			} else {
				return res.send("0");
			}
		} else {
			return res.send("0");
		}
	}
});

// Websocket stuff

const websocketServer = new WebSocketServer({
	port: Config.ports.ws
}, () => {
	Console.printInfo(`WebsocketServer listening at ws://localhost:${Config.ports.ws}`);
	fastify.listen({ port: Config.ports.http, host: "0.0.0.0" }, (err, address) => {
		if (err) {
			Console.printError(`Error occured while spinning up fastify:\n${err}`);
			process.exit(1);
		}
	
		Console.printInfo(`Fastify listening at ${address.replace("0.0.0.0", "localhost")}`);
	
		Console.printInfo("MultiProbe is ready to go!");
	});
});

function sendToAllButSelf(user:RemoteUser, data:Buffer) {
	users.forEach(otherUser => {
		if (otherUser.id !== user.id && otherUser.currentURL === user.currentURL) {
			otherUser.send(data);
		}
	});
}

function sendToAll(user:RemoteUser, data:Buffer) {
	users.forEach(otherUser => {
		if (otherUser.currentURL === user.currentURL) {
			otherUser.send(data);
		}
	});
}

function sendToAllInGroup(user:RemoteUser, data:Buffer) {
	users.forEach(otherUser => {
		if (otherUser.groupId === user.groupId && otherUser.userId !== user.userId) {
			otherUser.send(data);
		}
	});
}

websocketServer.on("connection", (socket) => {
	const myUUID = crypto.randomUUID();
	let user:RemoteUser;

	function closeOrError() {
		if (users.has(myUUID)) {
			users.remove(myUUID);

			const userLeftPacket = createWriter(Endian.LE, 5).writeByte(MessageType.ClientLeft).writeUInt(user.id).toBuffer();
			users.forEach(otherUser => otherUser.send(userLeftPacket));
			sendGroupUpdate(user);
		}
	}

	async function sendGroupUpdate(sendUser:RemoteUser, groupSend = false) {
		if (!sendUser || user.groupId === Number.MIN_VALUE) {
			return;
		}

		const usersInGroup = new FunkyArray<number, RemoteUser>();
		let totalUsernameLength = 0;

		await users.forEach(otherUser => {
			if (sendUser.groupId === otherUser.groupId && sendUser.userId !== otherUser.userId) {
				if (usersInGroup.has(otherUser.userId)) {
					totalUsernameLength += otherUser.username.length;
				}
				usersInGroup.set(otherUser.userId, otherUser);
			}
			if (!groupSend && sendUser.userId !== otherUser.userId) {
				sendGroupUpdate(otherUser, true);
			}
		});

		const writer = createWriter(Endian.LE)
			.writeByte(MessageType.GroupData)
			.writeShortString(sendUser.groupName)
			.writeUShort(usersInGroup.length);
		await usersInGroup.forEach(otherUser => {
			writer.writeShortString(otherUser.username).writeString(otherUser.rawURL);
		});

		const groupData = writer.toBuffer();

		sendUser.send(groupData);
	}

	socket.on("close", closeOrError);
	socket.on("error", closeOrError);

	socket.on("message", async (data) => {
		const reader = createReader(Endian.LE, data as Buffer);
		// There is absolutely no reason we should ever get
		// more than 50 bytes legit.
		if (reader.length > 0 && reader.length < 1024) {
			switch (reader.readByte()) {
				case MessageType.ClientDetails:
				{
					if (user !== undefined) {
						return;
					}
					const apiKey = reader.readShortString();
					const rawURL = reader.readString();
					const dbUser = await UserService.GetUserByAPIKey(apiKey);
					if (dbUser == null) {
						return;
					}
					const dbUserParty = await UserService.GetActiveParty(dbUser.Id);
					let dbParty: Party | null = null;
					if (dbUserParty) {
						dbParty = await UserService.GetParty(dbUserParty.PartyId);
					}

					let page = rawURL.toLowerCase().replace(".htm", "").replace(".html", "");
					if (page === "index") {
						page = "";
					}
					let lengthOfUsernames = 0;
					const usersOnPage = new Array<RemoteUser>();
					await users.forEach(otherUser => {
						if (otherUser.currentURL === page) {
							usersOnPage.push(otherUser);
							lengthOfUsernames += otherUser.username.length + 1; // + 1 for length byte
						}
					});
					const usersToSend = createWriter(Endian.LE, 3 + (usersOnPage.length * 12) + lengthOfUsernames).writeByte(MessageType.Clients).writeUShort(usersOnPage.length);
					for (const otherUser of usersOnPage) {
						usersToSend.writeUInt(otherUser.id).writeShortString(otherUser.username).writeFloat(otherUser.cursorX).writeInt(otherUser.cursorY);
					}
					if (dbParty) {
						user = users.set(myUUID, new RemoteUser(socket, dbUser.Username, page, rawURL, dbUser.Id, dbParty.Id, dbParty.Name));
					} else {
						user = users.set(myUUID, new RemoteUser(socket, dbUser.Username, page, rawURL, dbUser.Id, Number.MIN_VALUE, ""));
					}
					sendToAllButSelf(user, createWriter(Endian.LE, 6 + dbUser.Username.length).writeByte(MessageType.ClientJoined).writeUInt(user.id).writeShortString(dbUser.Username).toBuffer());
					user.send(usersToSend.toBuffer());
					sendGroupUpdate(user);
					break;
				}
				case MessageType.CursorPos:
				{
					if (user === undefined) {
						return;
					}
					user.cursorX = reader.readFloat();
					user.cursorY = reader.readInt();
					sendToAllButSelf(user, createWriter(Endian.LE, 13).writeByte(MessageType.CursorPos).writeUInt(user.id).writeFloat(user.cursorX).writeInt(user.cursorY).toBuffer());
					break;
				}
				case MessageType.Ping:
				{
					if (user === undefined) {
						return;
					}

					if ((Date.now() - user.lastPingReset) >= 1000) {
						user.allowedPings = 10;
						user.lastPingReset = Date.now();
					}

					if (user.allowedPings > 0) {
						user.allowedPings--;
						const cursorX = reader.readFloat();
						const cursorY = reader.readInt();
						const packet = createWriter(Endian.LE, 9).writeByte(MessageType.Ping).writeFloat(cursorX).writeInt(cursorY).toBuffer();
						sendToAll(user, packet);
					}
					break;
				}
			}
		}
	});
});

let isShuttingDown = false;
function shutdown() {
	if (isShuttingDown) {
		return;
	}
	isShuttingDown = true;

	Console.printInfo("Shutting down...");
	websocketServer.close(async () => {
		await fastify.close();
		clearInterval(sessionExpiryInterval);

		Console.cleanup();
		console.log("Goodbye!");
	});
}

process.on("SIGQUIT", shutdown);
process.on("SIGINT", shutdown);
//process.on("SIGUSR2", shutdown);